A choropleth map colors countries according to their economy type, with a custom ordinal color legend and hover interactions that highlight each nation. The visualization renders an SVG world map using a natural Earth projection via `d3.geoPath` and `d3.geoNaturalEarth1`, while supporting pan and zoom through `d3.zoom`. Data comes from the World Atlas TopoJSON and TSV datasets, processed with `topojson.feature` and loaded asynchronously. The color scale uses `d3.scaleOrdinal` with `d3.schemeSpectral`, and the legend is built with custom D3 enter/merge/exit selections.